A distance measurement apparatus using laser beams measures a distance to an object, for example, by emitting a pulsed laser beam and measuring the time of flight (TOF) ΔT, which is a round-trip time for the laser beam to return after being reflected by the object. Here, denoting the speed of light as c (about 300,000 km/s), the distance to an object may be obtained by (c×ΔT)/2.
In some cases, the measurement result of the distance measurement apparatus is output in the form of an image in which the distance to each range point is represented. An image output in such a form is capable of representing a distance to each range point, for example, by pixel color in accordance with the distance value. However, an area in which the distance is not correctly measured (a noise area) results from the influence of sunlight in some cases in an image in which the distance to each range point is represented.
As examples of the related art, Japanese Laid-open Patent Publication No. 2005-024370, Japanese Laid-open Patent Publication No. 2013-224915, and Japanese Laid-open Patent Publication No. 2005-291844 are known.